Simple Positive Displacement Pump Suitable for Pharmaceutical, Chemical, Biological, Viscous, Dense, Particulate Laden Fluids and Other Demanding Applications

ABSTRACT

A fluid pump for moving fluid from a first reservoir to a second reservoir is described. The fluid pump comprises a first reservoir containing a fluid, a second reservoir for receiving the fluid, at least one chamber subject to alternating high and low pressure, and an inlet valving device modulating or switching pressures to which the at least one chamber is exposed, causing the fluid to flow into the at least one chamber from the first reservoir when the at least one chamber is exposed to low pressure and causing the fluid to flow out of the at least one chamber into the second reservoir when the chamber is exposed to high pressure.

This application claims benefit of U.S. Provisional application Ser. No.62/231,755, filed on Jul. 15, 2015, and herein incorporated by referencein its entirety.

TECHNICAL FIELD

This application relates to the general field of fluid pumps, and moreparticularly, to pumps specialized for moving aggressive, delicate,unstable, flammable, particulate-laden, ultrapure, dense, or viscousfluids.

BACKGROUND

State of the art pumps or fluid moving devices largely fall into twolarge categories: dynamic or centrifugal, and displacement. The formertype uses some form of a fast moving impeller, while the latter uses adisplacement device such as a piston, diaphragm, or flexible tube.Either of these types can be driven by motors, air, exhaust gases froman engine, or other suitable form of energy.

In virtually all of the above cases, there are moving parts and seals incontact with the fluid being pumped. Seals deteriorate, generatecontaminants and particles, and have to be replaced periodically. Shaftswear out and have to be sealed from the power device (i.e. motor) andoften are exposed to the fluid, thus contaminating it and contributingparticles to it. Impellers are quite susceptible to attack by the fluid,even in cases of rather inert substances by cavitation. Impellers alsoexert considerable shear forces onto the fluid, sometimes deterioratingit. Diaphragms are flexed continuously and often fatigue andrupture—failing and exposing sensitive parts of the pump to the fluid.Pistons have to seal against the piston wall and can bind and theirseals wear, thus constantly contaminating the fluid with their wearby-products. In the absence of seals, they leak or bind against thepiston sleeve or wall.

Even pumps that magnetically levitate their impellers suffer fromserious limitations. Designs constraints make them hard to prime andtheir impellers wear and have to be replaced periodically. They alsoshear the fluids and make use of seals which also deteriorate.

SUMMARY

It is a primary object of the present disclosure to provide a method andapparatus to move fluids from one reservoir to another.

It is another object of the present disclosure to provide an apparatusthat can apply pressure to a fluid in such manner as to move it to aplace that is higher or at a distance from the container of origin.

A further object of the present disclosure is to provide an apparatusand method to move fluids from one reservoir to another requiring nomoving parts, or very few moving parts, such as pistons, impellers,diaphragms, lobed structures, shafts, among many others.

Yet another object is to provide an apparatus and method to move fluidsfrom one reservoir to another requiring no shaft seals or other sealsthat are frequently wetted by the fluids being moved, thus preventingcontamination and extending the life of the apparatus.

Yet another object is to provide a device and method that can be veryused in moving aggressive, delicate, unstable, flammable,particulate-laden, ultrapure, dense, or viscous fluids that may beotherwise difficult, potentially hazardous, or less practical to movewith a more conventional pump.

In accordance with the objectives of the present disclosure, a fluidpump for moving fluid from a first reservoir to a second reservoir isachieved. The fluid pump comprises a first reservoir containing a fluid,a second reservoir for receiving the fluid, at least one chamber subjectto alternating high and low pressure, and an inlet valving devicemodulating or switching pressures to which the at least one chamber isexposed, causing the fluid to flow into the at least one chamber fromthe first reservoir when the at least one chamber is exposed to lowpressure and causing the fluid to flow out of the at least one chamberinto the second reservoir when the chamber is exposed to high pressure.

Also in accordance with the objects of the present disclosure, a methodof pumping fluid from a first reservoir to a second reservoir isachieved. First and second reservoirs are provided. At least one chamberis connected by an inlet valving device to a high pressure source and toa low pressure source. The at least one chamber is connected by anoutlet valving device to the first and second reservoirs. Pressures aremodulated or switched, through the inlet valving device, into the atleast one chamber, causing fluid to flow into the at least one chamberfrom the first reservoir when the at least one chamber is exposed to lowpressure and causing fluid to flow out of the at least one chamber intothe second reservoir when the chamber is exposed to high pressure.

Further and also in accordance with the objects of the presentdisclosure, a method of moving fluid from one reservoir to a point ofuse of said fluid, or in general for moving fluid from one place toanother.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings forming a material part of thisdescription, there is shown:

FIG. 1 illustrates a side view of a first preferred embodiment of thepresent disclosure.

FIG. 2 illustrates a side view of a second preferred embodiment of thepresent disclosure.

FIG. 3 illustrates a side view of a third preferred embodiment of thepresent disclosure.

DETAILED DESCRIPTION

The present disclosure relates to a method and apparatus to move fluidsfrom one reservoir to another. This apparatus can apply pressure to thefluid in such manner as to move it to a place that is higher or at adistance from the container of origin. In contrast with conventionalpumps, the apparatus and method of this disclosure requires no movingparts, or very few moving parts, such as pistons, impellers, diaphragms,lobed structures, shafts, among many others. Also, the apparatus andmethod described herein requires no shaft seals or other seals that arefrequently wetted by the fluids being moved, thus preventingcontamination and extending the life of the apparatus. The device andmethod subject of the present disclosure can be very useful in movingaggressive, delicate, unstable, flammable, particulate-laden, ultrapure,dense, or viscous fluids that may be otherwise difficult, potentiallyhazardous, or less practical to move with a more conventional pump.Industries such as biomedical, medical, chemical, semiconductor,analytical, petroleum, among many others, may benefit from such a fluidmoving device and method.

Referring now more particularly to FIG. 1, a first preferred embodimentwill be described. A reservoir 10, which can be filled with fluid 20 isshown. The interior of reservoir 10 is alternatingly subject to high andlow pressures. In a typical embodiment, an inlet valving device 30(which can be comprised of a plurality of pneumatic valves, electricvalves, electro-pneumatic valves, flapper valves, ball valves, floats,or combinations thereof, among others) can modulate or switch thepressure to which the inside of the chamber 10 is exposed, such thatfluid 20 can be made to flow into or out of the chamber 10. One or moreof the valving devices 30 can be proportional, multi-way, or the on/offtype, either passive or actuated.

The chamber 10 can have one or more openings 40, typically on top andbottom, to allow for the fluid and pressure to move in and out of thechamber. The openings can also be on the same side, opposite sides,rotated, or connected with tubes or other types of channels in such away that the above functions, or combinations thereof, are accomplished.

In a typical embodiment, the chamber would have a source of low pressure50 (i.e. vacuum) and a source of high pressure 60 (i.e. a suitablecompressed gas or other suitable fluid). The relative value of thesehigh and low pressures is referenced to atmospheric values, the valuespresent at the destination reservoir, or other suitable pressurereference. In a typical embodiment, a 3-way valving device 30 wouldalternatively select the low pressure source 50 to draw fluid into thechamber and the high pressure source 60 to eject it from the chamber.This valving device can be 3-way, on/off, or proportional, among othertypes. In a typical embodiment, a suitable valving device 70, chosenfrom the same categories as the inlet valving device 30, would allow thefluid to alternatingly enter the chamber 10 and leave the chamber. In atypical embodiment, the two aforementioned valving devices would work ina suitable coordinated or uncoordinated fashion to achieve the desiredfluid transport or motion.

In a typical embodiment, the inlet valving device 30 would expose theinterior of the chamber to the low pressure source 50 at the same timeas the outlet valving device 70 exposes its interior to a fluidreservoir 90. This action would cause the fluid to flow from the fluidreservoir 90 into the chamber 10. After a suitable time interval theinlet valving device 30 would switch to expose the chamber to the sourceof high pressure 60 while in a suitable coordinated or uncoordinatedfashion, the outlet valving device 70 switches to expose the chamberinterior to an outlet path 100. The execution of one or more of thecycles described herein, or modifications thereof, would cause a fluidto be moved from a source 90 to a destination 110 in which these sourceand destination reservoirs can be at the same or different pressures orheights.

In a preferred embodiment, the fluid level is sensed at one or moreappropriate locations by sensors capable of producing a detectablechange of state in the presence of fluid within their sensing range. Thelevel reached by the fluid during any part of the cycle described abovecan also be sensed in a variety of other ways, such as by a timeinterval (fixed or variable), floats, magnetic switches, capacitivedevices, and optical devices, among other types. The fluid level can becontrolled in conjunction with the pressure fluctuations in the chamber,with passive valving systems, such as floats, flap valves, ball valves,or combinations thereof, among others. In a preferred embodiment, thelevel sensing switches are of the optical type and produce a detectableelectrical state change on their output when liquid is present withintheir sensing range. These can be located in a variety of suitablepositions, such as near or at the bottom 120 of the chamber 10, and/orat or near the top 130 of the chamber 10. In a preferred embodimentoptical switches 120, 130 control a pair of 3-way valves 30, 70 workingin tandem to periodically fill and empty the fluid in the chamber thusproducing the desired fluid motion or pumping action. In anotherembodiment, there may be only one optical switch located at or neareither end of the chamber in combination with a delay-on or delay-offmechanism, thus fixing the time that either the low pressure or the highpressure are acting upon the chamber, and thus taking fluid in orejecting it. One or more of these cycles can be repeated to produce thedesired pumping action. The above operating mode can be achieved withsimple components and made to operate in an autonomous fashion uponpower up, without the need for external program control. The term 3-wayvalve is intended to describe a general type of valving device thatroutes the fluids in accordance to the purposes of this disclosure.Other types of valving devices may be used instead and are also subjectsof the present invention. It may be noted that use of switches asdescribed above provides a timing and synchronization function akin tothat provided in conventional pumping systems by mechanical or othermore conventional means (e.g. crankshafts, connecting rods, and pistons;or equivalent).

Alternatively, all or some of the switches and valves can be controlledby a control device that takes inputs from these devices and affects thestate of valves or switches in such manner as to achieve the desiredfluid moving action.

Such control device is particularly useful if more than one chamber isconnected in parallel, as illustrated in FIG. 2. In this secondpreferred embodiment, with more than one chamber 10 in parallel, thethroughput of the whole apparatus increases and the flow becomesproportionally smoother. In this embodiment, the chambers can be timedsuch that some of the chambers are being filled while others areejecting the fluid, thus accomplishing a more continuous flow. Whenconnected in this manner, the flow from one chamber can be preventedfrom flowing into another by appropriate use of directional valves 140.As many chambers as practical can be connected in the above describedfashion. With a larger number of chambers and an appropriate fill/ejectsequence, the device and method described herein would achieve asubstantially fluctuation-free flow without the aid of dampeningdevices.

In addition, the device and method of the present disclosure times itsflow into and out of the chamber or multiplicity of chambers in theabsence of a hardware link, crankshaft, connecting rod, piston or othersimilar device. The timing of one chamber and the synchrony of amulti-chamber device can be controlled by timing of the valving devicesor by a combination of switches 120, 130 and a controlling device.

In a preferred embodiment, the switches 120, 130 are optical and thecontrolling device is a microcontroller running suitable software. It isevident to anyone versed in the art that many implementations andvariations of these schemes are possible without departing from thescope and sequence of the present disclosure.

The flow out of the chamber 10 can be placed on hold, pulsed ormodulated by using an additional valving device 150 in the output pathin a third preferred embodiment, as illustrated in FIG. 3. It should beobvious that many other embodiments are possible and are also subject ofthis disclosure. It should also be evident that many other arrangementsof valving devices, chamber arrangements, chamber geometries andlayouts, low pressure sources and low pressure generating devices, highpressure sources and high pressure generating devices are possible andare also subject of this disclosure.

It should be noted in the present disclosure, the absence or nearabsence of shaft seals, piston seals, or other seals, and othercomponents frequently wetted by the fluids being moved, thus preventingcontamination and extending the life of the apparatus. There is also asubstantial lack of moving parts, such as shafts, pistons, diaphragms,impellers, cams, pushrods, among others. The lack of moving parts andwetted seals make the device and method subject of this disclosureparticularly rugged and suitable for a great variety of applicationswhere chemical resistance, high purity, low particle generation,component longevity, among other desirable properties, are desired.

An additional feature of the device subject of this disclosure is itsdelicate handling of the fluid and the near absence of shearing forcesbeing exerted onto the fluid being moved thus making it particularlysuited for delicate fluid that may be affected by said shearing forces.

Further, unlike many other fluid moving devices, the device and methodsubject of this disclosure is self-priming and does not require anyadditional steps or aids to initiate its function.

The chamber or chambers of the device and method subject of thisdisclosure can range in volume from a fraction of a milliliter tohundreds, even thousands of gallons. Some materials that are suitablefor said chamber are steel, PTFE, acrylic, polycarbonate, other plasticsand composites, rigid or elastic materials, among many others.

Further, the chamber, valving devices, channels and other features ofthe device and method described herein, can be made either byconventional fabrication techniques, as well as by microfabricationtechniques (i.e. MEMS, LIGA, among others), as well as any othertechnique that can produce structures that can perform the functions ofthe device and method described herein. As such it is contemplated thatthe device and method subject of this disclosure can be incorporated inmicro- or nano-fluidic components. The structure and method of thisdisclosure is also suitable for planar applications where all or most ofthe devices are built into a substantially flat fashion. Suchapplications are contemplated and subject of this disclosure.

Applications

Multiple industries and applications would benefit from the device andmethod subject of this disclosure. The pharmaceutical and medicalindustries would benefit from a gentle, non-shearing, non-heating,ultra-clean, no particulate-generating, pumping device. The chemicalindustry and other chemical applications would benefit from an extremelyinert, self-priming, no-seals, no-moving parts, high throughput pumpingdevice.

Other applications that require the movement of fluids withparticulates, or are too viscous or dense for conventional pumpingdevices would benefit from the device and method subject of thisdisclosure.

In particular, the delivery of highly corrosive chemicals from theircontainers of origin (i.e. vendor bottles, carboys or drums) is achallenging application for a pumping device. A suitable device has tobe easily primed, it has to be corrosion resistant throughout (includingits control and motor device), it has to be susceptible to metering(i.e. deliver a controllable amount of fluid that can be dosed by asuitable device to achieve a desired volume), it has to move fluid at areasonable rate, it has to be able to handle bubbles which often form inchemical lines (i.e. hydrogen peroxide) without disruption or loss ofprime, and it has to be scalable (from cc/min to multi-liter/min). Inall these accounts the fluid moving device subject of this disclosure issuperior to the state of the art. Also, the reduced or absent use ofspark sources (e.g. motors) as well as friction between surfaces (e.g.pistons), make the method and apparatus subject of this invention alsosuitable for handling flammable or unstable liquids.

EXAMPLES

Example 1. Extracting corrosive chemicals from their bottles anddelivering them to a mixing container in a specified ratio. In apreferred embodiment, there is a single chamber as described above perchemical channel and a flow or mass metering device in the deliveryline. There is also a valve controlled by the metering device closingand opening as needed to achieve the desired volume per channel. Theentire system can be driven by compressed air and the chambers are 250ml in internal volume

Example 2. Two or more chambers as described above are linked inparallel and sequenced such that at any given time one or more aredelivering fluid and one or more are filling up. In such mode ofoperation the flow is substantially smooth (i.e. continuous and withsmall or no pressure fluctuations) while enjoying all the aboveenumerated advantages.

Alternatives and Variations

Although many embodiments, variations and combinations are conceivable,and also subjects of this disclosure; some such relevant embodiments andvariations are listed below:

The apparatus and method of the disclosure can be used for any fluid.The chamber or chambers can be of any geometry and any material. Anyother valving devices or devices may be used in any arrangement,geometry, or positioning. Any sources of low and high pressure, such aspumps, venturis, or others may be used. Any suitable gas or any suitablefluid conveying low and high pressure to the chamber and any of itscomponents may be used.

Any fluid sensing device or devices may be placed in any location orgeometry. Any method of timing the fluid intake or expulsion or anyother method of timing or sequencing multiple chambers may be used. Anyother processes, configurations, or form of energy source may be used.

The parts of the apparatus may be inverted, rotated or mirrored aboutany of its axes. Any number of chambers and any chamber shape or sizemay be used. Different process structures or fluid channels, internal orexternal, may be used. Any material, medium, or structure inside oroutside the fluid cavity or part of the fluid cavity may be used. Anydifferent type of fluid interaction element, any different type ornumber of fluid or exhaust channels, different arrangements, variations,or geometries of fluid and exhaust channels or different combinations offluid channels and valving devices, such as top access valving devicessuctioning or delivering fluids via tubes or channels incorporated intoor around the chamber or its components, or any other combinations orpermutations thereof may be used.

Different combinations or sequences or graduated or modulated variationor sequences of low pressure and high pressure applications to the fluidchamber channels and valving devices may be used. Additional componentsthat perform any other function, including, but not limited to,components that perform heating, scrubbing, agitating, stirring,cleaning, ultrasonic cleaning or excitation, laser exposure or exposureto any form of radiation or energy, among others, may be present. Theapparatus may be used or may have any number of its components in aninverted fashion (i.e. upside down) or at an angle from the horizontal.

The removal of fluid or fluids may be accomplished via other means orarrangements in addition to those described above, such as, but notlimited to, suction, gravity, chemical reaction, moving gas or fluid,displacement, mechanical, or electromagnetic. The delivery of fluid orfluids may be accomplished via different means or arrangements inaddition to those described above, such as suction, or any other means

Although the preferred embodiment of the present disclosure has beenillustrated, and that form has been described in detail, it will bereadily understood by those skilled in the art that variousmodifications may be made therein without departing from the spirit ofthe disclosure or from the scope of the appended claims.

What is claimed is:
 1. A fluid pump for moving fluid from a firstreservoir to a second reservoir comprising: said first reservoircontaining a fluid; said second reservoir receiving said fluid; at leastone chamber subject to alternating high and low pressure; an inletvalving device modulating or switching pressures to which said at leastone chamber is exposed, causing said fluid to flow into said at leastone chamber from said first reservoir when said at least one chamber isexposed to said low pressure and causing said fluid to flow out of saidat least one chamber into said second reservoir when said chamber isexposed to said high pressure.
 2. The fluid pump according to claim 1wherein said first and second reservoirs are at same or differentpressures or heights.
 3. The fluid pump according to claim 1 whereinsaid at least one chamber has one or more openings.
 4. The fluid pumpaccording to claim 3 wherein said at least one chamber has two openingsand wherein said two openings are on top and bottom of said at least onechamber, on a same side of said at least one chamber, on opposite sidesof said at least one chamber, or rotated from one another.
 5. The fluidpump according to claim 3 wherein said at least one opening is connectedwith tubes or other types of channels.
 6. The fluid pump according toclaim 1 wherein a source of said low pressure is a vacuum and wherein asource of said high pressure is a compressed gas or fluid underpressure.
 7. The fluid pump according to claim 1 wherein said inletvalving device comprises a plurality of pneumatic valves, electricvalves, electro-pneumatic valves, flapper valves, ball valves, floats,or combinations thereof and is proportional, multi-way, or an on/offtype, actuated or passive.
 8. The fluid pump according to claim 1further comprising an outlet valving device allowing said fluid to enteror leave said at least one chamber wherein said outlet valving device isproportional, multi-way, or an on/off type.
 9. The fluid pump accordingto claim 8 wherein said outlet valving device comprises a plurality ofpneumatic valves, electric valves, electro-pneumatic valves, flappervalves, ball valves, floats, or combinations thereof.
 10. The fluid pumpaccording to claim 1 wherein fluid level within said one or morechambers is controlled in conjunction with pressure fluctuations in saidone or more chambers, floats, flap valves, ball valves, sensors, orcombinations thereof.
 11. The fluid pump according to claim 10 whereinsaid fluid level is controlled by one or more sensors at or near a topportion and/or at or near a bottom portion of said at least one chamber,capable of producing a detectable change of state in the presence offluid within their sensing range wherein a level of said fluid can besensed.
 12. The fluid pump according to claim 11 wherein said one ormore sensors comprise optical sensors, floats, magnetic switches, orcapacitive devices.
 13. The fluid pump according to claim 8 furthercomprising a first optical switch controlling said inlet valving deviceand a second optical switch controlling said outlet valving devicewherein said inlet valving device and said outlet valving device are3-way valves and wherein said inlet and outlet valving devices work intandem to periodically fill and empty said fluid in said at least onechamber thus producing a desired fluid motion or pumping action.
 14. Thefluid pump according to claim 13 wherein all or some of said switchesand valving devices are controlled by a control device that takes inputsfrom said switches and valving devices and affects a state of saidvalves or switches in such manner as to achieve a desired fluid movingaction.
 15. The fluid pump according to claim 1 wherein a plurality ofchambers are connected in parallel and wherein some of said chambers arebeing filled while others are ejecting said fluid, thus accomplishing acontinuous flow of said fluid and wherein a directional valve connectedto each of said plurality of chambers prevents said fluid's flowing fromone to another of said plurality of chambers.
 16. The fluid pumpaccording to claim 1 further comprising an output path valving deviceallowing flow of said fluid out of said at least one chamber to beplaced on hold, pulsed or modulated.
 17. A method of pumping fluid froma first reservoir to a second reservoir comprising: providing said firstand second reservoirs; providing at least one chamber connected by aninlet valving device to a high pressure source and to a low pressuresource; connecting said at least one chamber by an outlet valving deviceto said first and second reservoirs; modulating or switching pressures,through said inlet valving device, to which said at least one chamber isexposed, causing said fluid to flow into said at least one chamber fromsaid first reservoir when said at least one chamber is exposed to saidlow pressure and causing said fluid to flow out of said at least onechamber into said second reservoir when said chamber is exposed to saidhigh pressure. Providing said second reservoir is a point of use of thefluid Providing said first reservoir is a bulk source.
 18. The methodaccording to claim 17 further comprising: controlling said inlet valvingdevice by a first sensor; and controlling said outlet valving device bya second sensor wherein said inlet valving device and said outletvalving device are 3-way valves and wherein said inlet and outletvalving devices work in tandem to periodically fill and empty said fluidin said at least one chamber thus producing a desired fluid motion orpumping action.
 19. The method according to claim 17 further comprising:providing an optical switch located at or near either end of said atleast one chamber in combination with a delay-on or delay-off mechanism,thus fixing the time that either said low pressure or said high pressureis acting upon said at least one chamber, and thus taking said fluid inor ejecting it; and repeating cycles of said taking said fluid in andejecting said fluid to produce a desired pumping action.
 20. The methodaccording to claim 17 wherein movement of said fluid is accomplished bysuction, gravity, chemical reaction, moving gas or fluid, displacement,or mechanical, or electromagnetic means.